DOI: 10.5593/sgem2017/42/S17.087


J. Latosinska
Tuesday 12 September 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-07-2 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 42, 699-706 pp, DOI: 10.5593/sgem2017/42/S17.087


Sewage sludge ash, a by – product of municipal sewage sludge thermal utilization, is one of the complex anthropogenic and potentially useful materials. The innovative proposal of sewage sludge ash usage is to use it as a raw material for synthetic zeolites. This article shows results of zeolitization of sewage sludge ash by the direct hydrothermal method and the indirect fusion method. Zeolitization of sewage sludge ash was conducted at the activation time of 12 hours, the activation temperature of 60oC, the crystallization temperatures of 60oC and 90oC, the crystallization time of 72 hours as well as SSA:NaOH ratios of 1:1.8. Sewage sludge ash used in the study was obtained as a result of sewage sludge incineration in a laboratory furnace. The research on sewage sludge ash before and after the process of zeolitization included the identification of a phase composition, the evaluation of grain structure changes and the results of cation exchange capacity. The obtained zeolites were hydroxy sodalite and zeolite X. It was found that a better method for the synthesis of zeolites is the indirect fusion method than the direct hydrothermal method. All the samples after zeolitization with the indirect fusion method had zeolite X, whereas after the direct hydrothermal method none of them did. A higher crystallization temperature is favorable for the formation of hydroxy sodalite regardless of the method of zeolitization. Moreover, zeolitization by the indirect fusion method caused a positive increase of the cation exchange capacity.

Keywords: sewage sludge ash, zeolitization, hydroxy sodalite, zeolite X, cation exchange capacity